Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, USA.
Virus and Prion Research Unit, National Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Ames, IA, USA.
Sci Rep. 2020 May 6;10(1):7640. doi: 10.1038/s41598-020-64456-9.
Chronic wasting disease (CWD) is a rapidly spreading prion disease of cervids, yet antemortem diagnosis, treatment, and control remain elusive. We recently developed an organotypic slice culture assay for sensitive detection of scrapie prions using ultrasensitive prion seeding. However, this model was not established for CWD prions due to their strong transmission barrier from deer (Odocoileus spp) to standard laboratory mice (Mus musculus). Therefore, we developed and characterized the ex vivo brain slice culture model for CWD, using a transgenic mouse model (Tg12) that expresses the elk (Cervus canadensis) prion protein gene (PRNP). We tested for CWD infectivity in cultured slices using sensitive seeding assays such as real-time quaking-induced conversion (RT-QuIC) and protein misfolding cyclic amplification (PMCA). Slice cultures from Tg12, but not from prnp mice, tested positive for CWD. Slice-generated CWD prions transmitted efficiently to Tg12 mice. Furthermore, we determined the activity of anti-prion compounds and optimized a screening protocol for the infectivity of biological samples in this CWD slice culture model. Our results demonstrate that this integrated brain slice model of CWD enables the study of pathogenic mechanisms with translational implications for controlling CWD.
慢性消瘦病（CWD）是一种迅速传播的鹿科动物朊病毒病，但仍难以进行发病前诊断、治疗和控制。我们最近开发了一种器官型切片培养测定法，使用超灵敏朊病毒接种来灵敏检测瘙痒病朊病毒。然而，由于鹿（Odocoileus spp）到标准实验室小鼠（Mus musculus）之间存在很强的传播障碍，因此尚未为 CWD 朊病毒建立这种模型。因此，我们使用表达麋鹿（Cervus canadensis）朊病毒蛋白基因（PRNP）的转基因小鼠模型（Tg12）开发并表征了 CWD 的离体脑切片培养模型。我们使用实时震动诱导转化（RT-QuIC）和蛋白错误折叠循环扩增（PMCA）等敏感接种测定法，在培养的切片中测试了 CWD 的感染性。来自 Tg12 的切片，但不是来自 prnp 小鼠的切片，对 CWD 呈阳性。切片产生的 CWD 朊病毒有效地传播到 Tg12 小鼠。此外，我们确定了抗朊病毒化合物的活性，并优化了在该 CWD 切片培养模型中检测生物样本感染性的筛选方案。我们的结果表明，这种 CWD 集成脑切片模型能够研究具有控制 CWD 的转化意义的发病机制。
